A Bayesian sequential design with binary outcome

Several researchers have proposed solutions to control type I error rate in sequential designs. The use of Bayesian sequential design becomes more common; however, these designs are subject to inflation of the type I error rate. We propose a Bayesian sequential design for binary outcome using an alpha‐spending function to control the overall type I error rate. Algorithms are presented for calculating critical values and power for the proposed designs. We also propose a new stopping rule for futility. Sensitivity analysis is implemented for assessing the effects of varying the parameters of the prior distribution and maximum total sample size on critical values. Alpha‐spending functions are compared using power and actual sample size through simulations. Further simulations show that, when total sample size is fixed, the proposed design has greater power than the traditional Bayesian sequential design, which sets equal stopping bounds at all interim analyses. We also find that the proposed design with the new stopping for futility rule results in greater power and can stop earlier with a smaller actual sample size, compared with the traditional stopping rule for futility when all other conditions are held constant. Finally, we apply the proposed method to a real data set and compare the results with traditional designs.     

基于全球商品流量表的中国大陆贸易影响力测算

文章利用国际货币基金组织(IMF)公布的各国(地区)进出口数据,编制了2015年全球商品流量表(G-CFM),描绘了国家(地区)间商品贸易网络关系,采用网络分析的方法对全球商品贸易格局进行了分析,发现了在全球商品贸易中以美、中、德为中心,世界各国紧密交织的网络特征,最后用投入产出方法分析了中国大陆的贸易影响力,测算了中国大陆进出口贸易对不同国家(地区)以及对全球的影响.     

Examining identity development among gay men of color

Within the past few decades, there has been an explosion of articles examining “gay identity.” Yet, much of this work continues to center on the experiences of gay White men or fail to adequately examine the process of identity development, even when “identity” is central to the discussion. This review outlines 4 theoretical perspectives used to explore gay men of color and identity development. Taken together, these 4 perspectives can offer a rich opportunity to explore the ways that gay men of color come to develop an identity that simultaneously addresses their racial and sexual identities. I argue that examining identity development among gay men of color can help sociology better understand the identity process and provide new insights into examining intersectionality by demonstrating that identities are not only intersectional but also contextual.     

Estimation of variance in bivariate normal distribution after the preliminary test of homogeneity

A preliminary test estimator of variance in the bivariate normal distribution is proposed after the Pitman–Morgan test of homogeneity of two variances. The bias and mean square error of the estimator are derived. The relative efficiency (RE) of the preliminary test estimator is studied. Computations and 3D graphs of RE for different parameters are analyzed. In order to get the maximum RE, recommendations of the significance level for the preliminary test are given for various sample sizes by using the max–min criterion.     

ON THE DESIRABILITY OF TAX COORDINATION WHEN COUNTRIES COMPETE IN TAXES AND INFRASTRUCTURE

This article contains two distinct messages. First, when jurisdictions compete in two independent strategic variables, the decision to coordinate on one variable (a tax rate) induces a carry‐over effect on the unconstrained instrument (infrastructure expenditures). Consequently, classical results of the tax coordination literature may be qualified. A second message is that the relative flexibility of the strategic instruments, which may depend on the time horizon of the decision making, does matter. In particular, tax coordination is more likely to be detrimental (in terms of revenue and/or welfare) when countries can compete simultaneously in taxes and infrastructure, rather than sequentially. The reason is that simultaneity eliminates strategic effects between tax and nontax instruments. (JEL H21, H87, H73, F21, C72)     

The Role of Family Behaviors in Determining Income Distribution: The Case of South Korea

In this article, we examined what has contributed to the worsening income inequality and poverty between 1996 and 2011 in South Korea. We used a rank-preserving exchange method and a conditional reweighting method to assess the roles of family behaviors—including female labor force participation and family structure—characteristics of household heads, and men’s earnings. The results showed that the change in men’s earnings was a dominant factor in accounting for the increasing income inequality and poverty. The change in age and education among household heads also contributed significantly to the worsening income distribution. The change in family structure mainly affected the income disparity among lower-income families and increased poverty. The rise in women’s labor force participation improved the income distribution but not considerably. The distributional roles of family have not worked to prevent or reverse the worsening income distribution in the past few decades in South Korea.     

Improved upper bound for the degenerate and star chromatic numbers of graphs

Let \(G=G(V,E)\) be a graph. A proper coloring of G is a function \(f:V\rightarrow N\) such that \(f(x)\ne f(y)\) for every edge \(xy\in E\). A proper coloring of a graph G such that for every \(k\ge 1\), the union of any k color classes induces a \((k-1)\)-degenerate subgraph is called a degenerate coloring; a proper coloring of a graph with no two-colored \(P_{4}\) is called a star coloring. If a coloring is both degenerate and star, then we call it a degenerate star coloring of graph. The corresponding chromatic number is denoted as \(\chi _{sd}(G)\). In this paper, we employ entropy compression method to obtain a new upper bound \(\chi _{sd}(G)\le \lceil \frac{19}{6}\Delta ^{\frac{3}{2}}+5\Delta \rceil \) for general graph G.     

明末至清中叶白山派发展述略

本文首先考察了玛哈图木·阿杂木其人其事与白山派的关系,其次着重探讨白山派的早期沿革史,重点放在阿帕克和卓以前的历史活动上.因这段历史比较模糊,易产生混乱,而阿帕克和卓以后的历史发展较清晰,且学术界作过不少研究,所以就这段历史略加叙述.     

《诗经》与先秦崇玉习俗

<诗经>通过日常生活和礼仪生活用玉的描写,生动地反映了先秦崇玉习俗的各个侧面.我们通过对这些材料的梳理,可以看出:玉是先秦时期沟通世俗与神圣的媒介,<诗>中的玉意象也折射出人们心灵世界的光芒.     

黎族"禁"习惯法的演变

"禁"是黎族传统文化中特有的一种现象.黎族"禁"习惯法主要包括"查禁"和"除禁"两个方面."禁" 习惯法的演变经历:产生、兴盛、衰落、消亡四个阶段.这一演变过程与黎族社会历史类型的转变相对应,是内外因长期综合作用的结果.